1. Field of the Invention
This invention relates to a locking device and more particularly to a keyless combination or dial lock for use on slide fasteners and other closure articles for security purposes.
2. Prior Art
Many lock devices have been proposed for locking slide fasteners by means of a pair of sliders adapted to open and close the slide fastener from both directions. One such slider lock as disclosed in Japanese Utility Model Laid-Open Publication No. 51-101204 comprises a projecting prong in one slider body and a lock pin in the other slider body, the prong and the pin being releasably engageable by a key. Another prior art lock is disclosed in Japanese Utility Model Laid-Open Publication No. 53-36903, which lock comprises a pair of annular swivels, one on the head portion of each of two companion sliders, the two swivels being juxtaposed and locked together by a locking member such as a padlock.
Since the above prior art slider locks were both unitary with the slider body, it was necessary to change the whole sliders with those of different designs and shapes from a limited selection to meet the customers' needs which would literally add to the cost of relatively expensive sliders with locks. The prior art slider locks were key-operated and hence care would be always required so as not to lose the key.
Some keyless dial locks are also known but are not entirely satisfactory in respect of the efficiency and reliability of locking operation particularly when they are applied to slide fasteners.